Tech 2 won't update since the modpacks.xml file is wrong for it. there is a comma (,) instead of semi-colon (;) separating the 1.1.7 and 1.1.6 versions in the file.. the launcher thinks the version is 1.1.7,1.1.6
You can get around it by editing the modpacks.xml locally, setting it to read only...